Loosing the will to live

[gripper]

I took the IP2 to France for the international NOC rally and on about four occasions it refused to start, plenty of cranking but no light up. Then for no good reason it would start. On the return journey I noticed a slight hesitancy in the cruise, almost like someone just tugging at your waistband, I presume a misfire. Wouldn't start at the ferry terminal (nightmare) then did. Wouldn't start in Kent, then did and the remainder of the journey to Shropshire was good. I didn't use the bike for about 10 days and now it won't start at all. I have one of Graham's digital ignitions fitted. I have a flashing red led on this box, sparks at the plug, fuel in the chambers, just no light up. I re-fitted my old sparkright ign box, still sparking, no light up, back to the digi box, plenty of cranking and fuel and sparks just no firing. I must admit to being baffled. I don't see how the ignition timing can move to cause a problem so the floor is open to all offers and suggestions. Please.Dave Evans

[Richard Negus]

Dave,The first question is whether it has a steady idle when the engine is hot; poor or no idle usually suggests low compression which would make a hot re-start difficult. The digital ignition compensates for this by having the first 25 turns at full advance, even when the engine is hot, but if you've cranked more than that with a hot engine, I think it reverts to full retard like a Boyer. Flicking the kill switch should re-set it to full advance again. Your description suggests an intermittent loss of compression such as might be caused by one or more sticking rotor gas seals. Broken/worn out pin seal springs perhaps?Also possible is fuel starvation; vacuum pipe leaking, fuel tap gunged, filter partially blocked.Is your side stand cut-out switch connected, and perhaps just on the point of 'breaking' and affected by road vibration?Do you have a pre-Boyer ignition trigger with encapsulated coil? They are prone to cracking the wire insulation where they exit the coil and might be shorting intermittently.

[Dell Boy]

I had the same problem with my first IP2. It was a bad/broken? wiring connection somewhere around the headstock. By moving the loom about I could get a connection & start the bike. It always happened if the steering had been on full lock (cant remember which way) either parked or turning a tight circle. I never found the cause.Derek F.

[gripper]

Thanks for your suggestions gents. Prior to the problem the idle speed was rock steady and restarting was not generally a problem, cranking with the plugs out results in plenty of fuel vapour and the plugs are wet. Cranking with the plugs held against the engine produces a spark and the engine has not got hot to switch in the retard as it hasn't started. I'm thinking along the lines of flooded exhaust pipes with too much fuel quenching the spark but really the fuel should not get drawn back into the chamber. It's frustrating particularly as the weather is picking up.

[gripper]

I may be getting somewhere. I'm beginning to suspect the hall effect pickup. I have removed the digi box and jury rigged the old sparkright unit and hitachi coils. Holding the plug against the engine, on the LH plug I'm getting one spark as I press the starter button, on the RH plug I'm getting one spark as I release the start button. What I'm not getting is repeating sparks in time with the engine cranking. Strange but true. (I must of got a spark as I turned the ign off because the backfire was awesome, might of had the pu wires round the wrong way) Are the hall effect senders special to Nortons or are they a Maplin item and the $50,000 question how much are they. Pity the gearbox cover has to come off to get at it though.

[Richard Negus]

Dave,I don't think you have a Hall-effect sensor!Sparkrite, Boyer and Startright digital systems use an inductive trigger which only has two wires. These triggers were made first by Sparkrite (identified by an encapsulated cylindrical coil and grey or grey/black wires) or by Boyer (visible coil windings and red or white wires). Resistance of the Boyer type is around 164 ohms, the earlier ones slightly less (memory fade). Both have a magnet, the flywheel step passing changes the magnetic field and generates a small low-voltage pulse. Trigger air gap is critical to correct function, around 0.4 mm +/- 0.1 mm.A Hall-effect sensor has three wires, one ground, one +5 volts, and the third is the output signal. It also contains a magnet and acts like a switch, giving a brief 5 volt output on the signal wire when the magnetic field is interrupted by the flywheel step.Used on the Norton Digikit and millions of aero and automotive timing applications, including the Mid-West injected single and twin rotor engines. The air gap is not critical, 2.00 mm +/- 0.5 mm is good enough.I agree that taking the gearbox cover off to access the trigger is a pain, which is why many of the factory test bikes had the front of the cover sawn off. I have a few good used Boyer triggers if you need to borrow one for trial.

[gripper]

Many thanks for that Richard, I thought they all were hall effect, every day's a school day. Mine is the pre boyer item. I'll PM you regarding borrowing one TVM Dave.

[Richard Negus]

Mine is the pre boyer item.Dave.

Look closely where the wires come out of the encapsulation. I've seen the wire insulation hard and cracked and the copper wires visible. It's possible there may be an intermittent short there.

[JohnOR]

Hi DaveTry a good 12v supply to the ignition box if the ignition relay contacts are poor you will have these symptons. I reworked the supply to the box and the problem went. I did this a few years back will see if I can find my notes for the mod.Best of luck regards John

[gripper]

Hi John, I think that is where the fault lies, I managed to get a brief fire up by running a wire from the +ve side of the battery direct to the white power input to the digi box. There is an orange wire that needs a 12v supply, labelled cranking boost. It should come from the start solenoid. I will probably feed that direct from the battery as well. The fire up was brief because I still have the gearbox cover off and no oil in it. Richard's loaned trigger unit is working, hopefully I have a new one en-route from Graham at Startright. I would be interested to see your wiring solution to the voltage drop from the relay. And do I really need a relay? I suppose I could feed the digi box direct from the ign switch (yellow /white)Dave

[JohnOR]

Hi DaveSorry can't find details of mod but found note to say I moved wires in 1999.Looking at the workshop manual page H6 explains the very long route of the12V ignition supply (2 fuses and 2 bulkhead connectors).The factory mod fortwin rotor idle was to fit a relay so a good supply went to the ignition box.On looking at the wiring of my bike my mod was to jump this supply to the retard boxRather than letting it run off the white/yellow supply.In summaryrelay coildouble wire white/yellow (ign. live)black (earth)relay contactsbrown/green from fuse to batteryred(advance/retard box lgn. live feed)+white/yellow(Sparkrite supply)On reflection my mod was not because of poor relay but poor connectorsHope this helps John

[Richard Negus]

In the original Boyer, the orange wire starts from the starter motor terminal of the solenoid and is only live when the solenoid is energised. That orange wire goes to the Boyer box and comes out as the brown/white feed to the coils; it isn't connected to any of the gubbins inside the box.The brown/white goes to coils +ve, bypassing the ballast resistor and giving the coils full battery voltage so long as the starter button is pressed. Of course, the starter motor is taking around 100 amps from the battery so its voltage is reduced below the normal 12.7 volts. As the coils are 6 volt type, there's still a good spark. When the button is released, and we assume the engine is running, that bypass is ended and the ballast resistor drops battery voltage to the coils to around 9 volts which again produces a very good spark.When the ballast resistor corrodes and goes open-circuit, that explains why the engine starts and runs only when the button is pressed.As the Startright digital box was designed to be a direct replacement for the Boyer, it has the same wire connections.

[gripper]

I seem to be getting nowhere fast. I had a brief fire up by jury rigging the supply to the digi box direct from the battery but I couldn't sustain it due to no oil in the gearbox etc. I have a new trigger and with either system, start right digital or spark right electronic, I have a very good spark at the plugs. The plugs are coming out soaked, cranking with the plugs out produces clouds of fuel ,vapour I'm just not getting a light up. It's almost like the ign timing is massively out ( i've reversed the trigger leads and not even had it ignite in the exhaust pipe which is common) I've tried a completely separate car battery to power the ign to ensure no voltage loss from the starter motor. I'm rapidly running out, no, I've run out of ideas. The digi box is away for testing but I doubt it's faulty as the old sparkright box is producing a spark. Mayday mayday mayday I'm going down (but not in flames)

[Howell]

Hi Gripper,Could it be too rich, due to the cold start "O" rings leaking?Regards,Howell

[Interpol2471]

I also had a similar problem casued by my carbs after a long run. The nut that holds the main jet in place had come loose and dropped into the bottom of the float bowl chamber causing the carb to flood, maybe Howell has a point and look at those as well if you have a good consistent spark.

[gripper]

I've had some success at last with the old Sparkright setup. I disconnected the vacuum pipe to the petrol tap and cranked for about a minute and blew all the collected fuel out of the plug holes. dry plugs in and she caught just, bit reluctant to run initially but picked up eventually. The old trigger unit tested at 340 ohms, compared to the new one and Richards loaned one at 162 ohms. I'm pretty sure that's where the original problem was. The rest of it was a combination of issues, mainly flooding. Anyway I've created a new olympic sport it's called throwing the garage smoke detector discus style. I'm the world record holder at the moment at 25 yds

[gripper]

I have a bike that is up and running at last. The trigger unit was the culprit and a new one solved the problem. I had the ignition unit tested, no fault found. The orange wire feeding the digi box needs power all the time. Powering it from the output side of the solenoid results in ignition, but only as long as the start button is being pressed. (I have 12volt coils and no ballast resistor) I will find out more on this when I phone Julian Kemp at Minimag later this evening.

[Richard Negus]

Dave,You're missing the live feed that used to go via the ballast resistor to the original 6 volt coils. I think they're brown/white. Connecting those leads to the ballast together should solve the problem.Without the ballast you don't really need the orange wire connected.R.

[gripper]

Hi Richard, the bike is an IP2 and never had a ballast resistor, I still need power to the orange lead going into the Startright ignition box, as soon as it is removed, despite there being power to the white (Feed) lead, the engine stops. As an aside, the bike is much more responsive from the off with no hesitancy at all in the pick up, unlike before, so my trigger has been suspect for quite some time. (story of my life) I'm lucky it managed to get me all the way to France and back, though a couple of times I wondered. Next problem is a slightly sticky pair of butterfly throttle valves at the top end of the arc. I could fit a stronger spring but that treats the symptoms not the cause.

[Pike]

I had lent my IP2 to my brother who returned it broken with the comment "it just stopped". Fortunately, I was able to get out and check things for the first time yesterday (Sun!!!! What a rare treat in the UK) and found I wasn't getting any spark to either plug but plenty of fuel. I've removed the Sparkrite unit to test on the bench at work (we have clever electronics chaps here) but reading up makes me suspect the pickup sensor. What can be done if it is duff? As it says elsewhere on this thread, is there something broadly equivalent which can be made to fit? I haven't checked the gap because I wasn't suspicious and didn't want to drain the oil. Sounds like this will be my next job. I did at least check continuity on sensor and got a value of ~250 Ohms. Possibly a little high from what I read Any thoughts?Thanks in anticipationNobby No Sparks